Bale wrapping machines allow to wrap bales of hay with a plastic film in order to promote fermentation in order to produce silage. Bale wrapping machines are very popular due to their simplicity, their low cost of acquisition and their efficient performance.
In line bale wrapping machines, like those described in U.S. Pat. No. 4,793,124, U.S. Pat. No. 5,596,864, U.S. Pat. No. 6,070,400 are equipped with a rotatable bale wrapping ring on which 1 to 4 plastic film dispensers are installed. The plastic film on each plastic film roll is pre-stretched and spins around the bale thus limiting air infiltration and allowing for proper fermentation of the silage. The wrapping ring is activated as the bale of hay is fed through it so that a proper cylinder of plastic is wrapped around the bale. The bales are continually placed on the feeding side of the wrapping machine by an operator or via a bale storage trailer that is affixed to the bale wrapping machine. A pushing mechanism, found either on the bale wrapping machine or on the bale storage trailer, guides the bales through the activated rotatable bale wrapping ring and towards the discharge ramp. Once a bale has been fed though by the pushing mechanism, the pushing mechanism is retracted and waits for another bale to be loaded in order to repeat the cycle. The length of a wrapped bale row is variable and depends on the quantity of bales to be stored and the dimensions of the storage facility. It is quite frequent that bale cylinders are made in a reduced size to optimize storage.
To finish the wrapped bale cylinder, it is necessary to wrap and eject the last bales present on the machine. The majority of manufacturers propose the use of steel tubes that are introduced into the pushing mechanism to extend its range. This operation is manual, slow and exhibits risks for the safety of the workers. For example, Tubeline Manufacturing proposes a manual system at uses a transversal bar that the operator must displace between each push to be able to completely empty the loading side of the bale wrapping machine. This principle is disclosed in U.S. Pat. No. 6,089,003 (FREY 2000).
In light of this, it is desirable to have an automatic bale unloading device for an in-line wrapper or for a trailer attached thereto that is inexpensive, easy to maintain, and easy to manufacture.